package com.example.text.chat;

import io.netty.channel.Channel;
  import io.netty.channel.ChannelHandlerContext;
  import io.netty.channel.SimpleChannelInboundHandler;
  import io.netty.channel.group.ChannelGroup;
  import io.netty.channel.group.DefaultChannelGroup;
  import io.netty.handler.ssl.SslHandler;
  import io.netty.util.concurrent.Future;
  import io.netty.util.concurrent.GenericFutureListener;
  import io.netty.util.concurrent.GlobalEventExecutor;
  
  import java.net.InetAddress;
  
  /**
   * Handles a server-side channel.
   */
  public class SecureChatServerHandler extends SimpleChannelInboundHandler<String> {
  
      static final ChannelGroup channels = new DefaultChannelGroup(GlobalEventExecutor.INSTANCE);
  
      @Override
      public void channelActive(final ChannelHandlerContext ctx) {
          // Once session is secured, send a greeting and register the channel to the global channel
          // list so the channel received the messages from others.
          ctx.pipeline().get(SslHandler.class).handshakeFuture().addListener(
                  new GenericFutureListener<Future<Channel>>() {
                      @Override
                      public void operationComplete(Future<Channel> future) throws Exception {
                          ctx.writeAndFlush(
                                  "Welcome to " + InetAddress.getLocalHost().getHostName() + " secure chat service!\n");
                          ctx.writeAndFlush(
                                  "Your session is protected by " +
                                          ctx.pipeline().get(SslHandler.class).engine().getSession().getCipherSuite() +
                                          " cipher suite.\n");
  
                          channels.add(ctx.channel());
                      }
          });
      }
  
      @Override
      public void channelRead0(ChannelHandlerContext ctx, String msg) throws Exception {
          // Send the received message to all channels but the current one.
          for (Channel c: channels) {
              if (c != ctx.channel()) {
                  c.writeAndFlush("[" + ctx.channel().remoteAddress() + "] " + msg + '\n');
              } else {
                  c.writeAndFlush("[you] " + msg + '\n');
              }
          }
  
          // Close the connection if the client has sent 'bye'.
          if ("bye".equals(msg.toLowerCase())) {
              ctx.close();
          }
      }
  
      @Override
      public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {
          cause.printStackTrace();
          ctx.close();
      }
  }

